This is a request for funds to purchase a high-field multinuclear Fourier Transform nuclear magnetic resonance spectrometer. With this instrument the Major User group proposes to carry out health-related research in the following areas: 1) NMR studies of model hemes and heme proteins, including investigation of the role of axial ligand plane alignment and pyrrole substitution on the magnetic properties of ferriheme models; factors affecting the rate of electron self-exchange in model hemes; the effect of porphyrin ring distortion on the spectroscopic properties of model hemes; metal nucleus NMR studies of 59Co model hemes; the rate of heme rotation in ferrocytochrome b5; and the interaction of hemin with human serum albumin and hemopexin; 2) NMR studies of the effect of ionic strength and pH on the rates of proton exchange in ferro- and ferricytochrome c and lysozyme in the absence and presence of N-acetylglucosamine and its oligomers, to be used for comparison to the results of adiabatic compressibility measurements on the same systems; 3) NMR studies of the binding of sugars to the LamB protein of E. coli, including transferred NOE measurements to determine the conformation of small chain maltose derivatives, and 19F NMR studies of fluorinated glucose, maltose, and, if possible, longer chain maltodextrins; 4) NMR studies of energy transducing enzymes from muscle, including comparison of the structural dynamics of cardiac and skeletal myosin subfragment-1, and Yb3+ binding studies of the Ca2+ binding sites of CaATPase from sarcoplasmic reticulum; and 5) the use of NMR spectroscopy in structure determination of cyclopentanoid natural products synthesized from saturated endoperoxide intermediates. In addition, three minor users will utilize the NMR spectrometer to 6) investigate the mechanism of the formyltetrahydrofolate synthetase reaction; 7) identify the products of synthesis of boronic acid analogs of amino acid derivatives and investigate their actions as enzyme inhibitors; and 8) aid in identifying and determining the structure of secondary metabolites isolated from marine natural products.